1[transitive,intransitive]to have difficulty speaking because you cannot stop yourself from repeating the first sound of some words several timessynonymstammer+ speech‘W-w-what?’ he stuttered.stutter (something)I managed to stutter a reply.

2[intransitive](of a vehicle or an engine)to move or start with difficulty, making short sharp noises or movementsThe car stuttered along in first gear.